4
Helena 10000 7
Jason 20000 21
Kit 30000 21
LazyGuy 15000 7

list
changeAnnualLeaves Helena 14
exchangeSalaries Helena LazyGuy
addSalary Helena 5000
list

undo
undo
undo
list

redo
redo
redo
list

fire LazyGuy
fire Helena

list

undo
list

undo
list

redo
list